Comparing GHG Emissions of Residue-Based BECCS to Alternative Biomass Uses

Abstract

Bioenergy with carbon capture and storage (BECCS) holds promise for achieving negative greenhouse gas (GHG) emissions while generating electricity. When using forestry or agricultural residues as feedstock, BECCS may also avoid or reduce land-use based impacts compared to dedicated energy crops. It is, however, unclear how negative emissions from residue-based BECCS compare to alternative uses (bioenergy with no CCS, 2G ethanol, paper and boards, animal feed and decomposition) and how quickly BECCS can achieve climate benefits compared to these other uses. In this study, we used life-cycle assessment (LCA) to quantify supply chain emissions of BECCS for two power plants in the Netherlands, using residue-based wood pellets from Louisiana, USA, and sugarcane bagasse pellets from Louisiana and São Paulo, Brazil, as feedstock. Using an attributional LCA approach, we showed that the two BECCS plants combined use 7.5 Mt of biomassdry per year. This system generates between 10.3 and 11.1 TWh of electricity and provides 11.0 and 11.3 Mt CO2-eq. of negative emissions annually, for wood or bagasse, respectively. This results in a footprint of −0.63 (wood) and −0.65 (bagasse) t CO2-eq./twet biomass. Following a consequential approach, we contrasted the GHG emissions per tonne of biomass residue used for BECCS with those associated with alternative uses, accounting for the (avoided) emissions from any substituted products and electricity. Here, BECCS negative emissions of approximately −0.6 t CO2-eq./twet biomass compare favourably to emissions of alternative uses, which range from −0.3 to +0.12 t CO2-eq./twet biomass. This study showed BECCS' potential for achieving negative emissions and climate benefits compared to other biomass uses.